An exemplary, known from the prior art and similar to the above described solution, method of a localization of an object or person within the monitored geographical area is disclosed in the European patent application EP 0 583 623 A1. This method is realized with using a number of base stations and a number of localization transmitters. Each base station comprises at least one localization receiver and is assigned to a given and limited subarea of the monitored geographical area, wherein the base stations are distributed in such a manner that their subareas cover the whole monitored area. The localization transmitters are connected to subjects that are to be localized and transmit signals that are received by the localization receivers. The method comprises the following steps:
a) periodical emissions of a localization message comprising an identification code assigned to an identity of the subject to which a given transmitter is connected, wherein the emissions are realized by the localization transmitters;
b) receiving of the emitted localization messages by at least one localization receiver;
c) storing in a database of messages by the base station corresponding to a given transmitter from the stage b), records comprising identification codes contained in the emitted messages; and
d) retrieving the code corresponding to a given subject in the database.
An automation of known solutions of this type consists in a lack of a necessity of any interaction of a given subject the attendance of which is to be monitored on a given area. The one and only duty of a subject is to carry an identification transmitter with it. Such a system automatically determines an attendance of a given subject in the monitored area and determine a given localization transmitter incoming and outgoing respectively on and from the monitored area.
The essential disadvantage of such known solutions is a lack of a resistance thereof against an attempts of a simulation of attendance of a given subject assigned to a given localization transmitter by:                carrying in a transmitter onto the monitored area, leaving the transmitter in the monitored area, and subsequently coming out from the monitored area by the subject, the attendance of which are to be monitored, without the left transmitter;        carrying in a number of transmitters by one subject onto the monitored area;        exchanging transmitters between subjects.        
The only one known method for providing in such solutions a resistance against such attempts of an attendance simulation is to fixedly connect a transmitter to a given subject that is to be monitored in a manner disabling for an unauthorized detachment of a transmitter from the subject to which it is assigned. Such a solution may however not be used in each case.
The above presented exemplary disadvantages cause that such an automatic attendance monitoring, featuring apparently some advantages, have not as yet found a practical use, for example in working time registration systems where a use thereof seems to be particularly advantageous.
Practical solutions for a working time registration are still based solely on an entrance-exit terminals reading information from personal proximity cards of employees (for example RFID cards, cards provided with a bar code or cards with a magnetic strip) and employee biometric information during an employee approaching the terminal. For a correct registration these solutions require on each ingoing and outgoing episode, both in and out of the monitored work area, an interaction of an employee consisted in bringing a proximity card near to the terminal or an appropriate part of a body in a case of a biometry employment. Therefore in order to prevent for employees to passing through such terminals without reading of required data from a proximity card or without acquiring biometric information, such terminals have to be additionally provided with special gates that are open only after reading the required proximity card information or biometric data.
In such known systems an occurrence of reading of proximity card data or biometric data reading evidences solely a passing of a given employee through a terminal. Therefore in such solutions it is necessary to implement additional mechanisms (for example by an interaction with an employee, that by means of an appropriate user interface manually determines whether a given passing is an ingoing or an outgoing, or on the basis of a passing “history” analysis) specifying whether a given passing through a terminal constitutes an ingoing or an outgoing event, or simply to install individual entrance terminals and exit terminals.
Obviously in order to provide security and reliability for such a type of systems, their terminals have to be installed at all entrances and exits respectively into and out of the monitored working area. Therefore an employment of such systems is not possible in an obvious manner in a case of open working area, such as for example a construction site.
As a possibility of a simulation of an ingoing/outgoing of an employee assigned to a given proximity card is obvious, for example by providing a proximity card for reading in the terminal by a different employee not assigned to the card being read, the system of such a type have to be additionally provided with an additional appropriate security mechanism comprising for example an identity verification of an employee presenting a given proximity card, wherein the verification may for example comprise an acquisition of biometric information, photo- or video registration of an episode of bringing a card near to an entrance/exit terminal reader. However an automatic detection of such unauthorized operations using photo- and video registration may be in many cases impossible as it is difficult to recognize an image of a given employee in each situation and to automatically compare the image with a standard pattern.
Furthermore in many cases using biometric system for a working time registration may be restricted by legal restraints.
It is clearly visible that in a comparison with the automatic attendance monitoring solutions using active identification modules, the presently used working time registration systems are much more complicated with regard to a structure and a construction, and furthermore a proper operation thereof requires a considerably greater monitored employee involvement as such a proper operation is dependent on an employee goodwill and requires from an employee to do a greater number of operations for a proper registration of an ingoing or an outgoing episodes.